Package ca.uhn.hl7v2.util.idgenerator

Class HiLoGenerator

java.lang.Object

ca.uhn.hl7v2.util.idgenerator.IDGenerator.OrderedSupport

ca.uhn.hl7v2.util.idgenerator.HiLoGenerator

All Implemented Interfaces:

IDGenerator, IDGenerator.Ordered

Direct Known Subclasses:

DelegatingHiLoGenerator

public abstract class HiLoGenerator
extends IDGenerator.OrderedSupport

Abstract base class for a HiLo-style generator that cheaply generates "lo" IDs in memory but only seldomly increments (potentially more expensive) a "hi" ID, e.g. in a persistent store. The combination of "lo" and "hi" ID becomes the final ID returned to the caller.

Author:

Christian Ohr

Nested Class Summary

Nested classes/interfaces inherited from interface ca.uhn.hl7v2.util.idgenerator.IDGenerator

IDGenerator.Ordered, IDGenerator.OrderedSupport

Constructor Summary

Constructors

Constructor	Description
HiLoGenerator()

Method Summary

Modifier and Type	Method	Description
String	getID()	Generates and returns a new ID.
abstract long	getMaxLo()	Returns the maximum Lo ID (expect the Hi ID be incremented afterwards)
protected abstract long	getNextHiId()	Returns the next Hi ID
protected long	getNextLoId()	Returns then next Lo ID
void	reset()	Resets the generator
protected abstract void	resetHiId()	Resets the Hi ID

Methods inherited from class ca.uhn.hl7v2.util.idgenerator.IDGenerator.OrderedSupport

getIncrement

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

HiLoGenerator

public HiLoGenerator()

Method Details

getID

public String getID()
             throws IOException

Description copied from interface: IDGenerator

Generates and returns a new ID. Note: This method must be implemented to be thread-safe.

Returns:

a new ID.

Throws:

IOException

getNextHiId

protected abstract long getNextHiId()
                             throws IOException

Returns the next Hi ID

Returns:

the next Hi ID

Throws:

IOException

resetHiId

protected abstract void resetHiId()

Resets the Hi ID

getNextLoId

protected long getNextLoId()

Returns then next Lo ID

Returns:

reset

public void reset()

Resets the generator

Specified by:

reset in interface IDGenerator.Ordered

Overrides:

reset in class IDGenerator.OrderedSupport

getMaxLo

public abstract long getMaxLo()

Returns the maximum Lo ID (expect the Hi ID be incremented afterwards)

Returns:

the maximum Lo ID